The first evening of the NHL postseason did not disappoint.

Among other surprising storylines, the unquestioned championship favorite coughed up a lead and lost in stunning fashion, and two rookies lifted their respective squads to victory.

Here's what we gleaned from each of the five matchups on the opening night of playoff action:

Lightning take feet off gas after hot start

Everything was going according to the plan for the Tampa Bay Lightning in Game 1 against the Columbus Blue Jackets, but then the wheels completely fell off for the league's most dominant team.

After tying a franchise postseason record with three goals in the opening period, the Lightning surrendered four unanswered markers, including three in the third, en route to a shocking 4-3 defeat on home ice.

(Courtesy: Natural Stat Trick)

It's not uncommon for a team to ease up a bit with a lead, but to call this particular collapse unexpected would be an understatement.

Tampa Bay was 39-2-2 when leading after two periods in the regular season, while Columbus was 2-23-1 when trailing after 40 minutes, according to NHL.com's Tom Gulitti.

Islanders prove to be resilient

Buoyed by a predictably raucous Nassau Coliseum crowd, the New York Islanders persevered multiple times to earn their Game 1 victory over the Pittsburgh Penguins.

The Islanders thought they'd opened the scoring 33 seconds in, but Tom Kuhnhackl's goal was rightfully wiped out following an offside review, silencing the boisterous arena. However, Jordan Eberle tallied shortly thereafter, at the 1:40 mark, to whip the crowd into a frenzy again.

New York then rallied to win it after allowing Justin Schultz's late tying goal in the third. Josh Bailey buried the overtime winner after a great effort by Mathew Barzal less than five minutes into the extra frame.

The Islanders will need to show the same resiliency in hostile territory as well, but their ability to respond to adversity both early and late in Game 1 was the biggest reason they prevailed.

Binnington stays hot in playoff debut

Jordan Binnington didn't appear phased at all in his first-ever postseason game.

The rookie St. Louis Blues goaltender outdueled the more experienced Connor Hellebuyck of the Winnipeg Jets and allowed only one goal on 25 shots to lift St. Louis to a 2-1 victory in Game 1.

Binnington won 20 of his final 24 contests in the regular season, including eight of his last nine.

On Wednesday night, the 25-year-old proved fully capable of continuing that success in pursuit of the Stanley Cup with a stellar performance in his playoff debut.

Don't tell Heiskanen he's only 19 years old

Much like Binnington, Miro Heiskanen looked like a seasoned veteran in his first NHL postseason contest.

The young defenseman scored twice in the Dallas Stars' 3-2 victory over the Nashville Predators, netting a power-play goal on a wrister in the second period and firing another one home in the third.

Heiskanen also logged more than 23 minutes of ice time. That was about on par with his regular-season workload, but only one teammate (Esa Lindell) and one opposing player (Roman Josi) played more than Heiskanen in Game 1.

The rookie blue-liner has been one of the best and most underappreciated first-year players in the NHL this season, but he won't be undervalued for long if he keeps this up in the playoffs.

Golden Knights come out flat

What a difference a year makes.

The Vegas Golden Knights put forth a lackluster effort until the final minutes of their 5-2 defeat to the San Jose Sharks. The Golden Knights certainly didn't look like the team that overwhelmed so many opponents en route to their run to the Stanley Cup Final last season.

Vegas managed only five shots on goal in each of the first two periods, and got completely outplayed by San Jose in the possession department as well.

Sure, it was only one game, and it was also on the road against a very deep Sharks club, but the Golden Knights obviously need a better effort in Game 2 if they want to avoid digging themselves into a deeper hole.

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